Surveys

Underwater operations in progress until further notice by c/s ile daix in vicinity of trackline joining…

Irish Sea and St. George's Channel · HYDROLANT 874/21

What this record establishes

Archived notice · 2021-04-03 22:02Z

This notice comes from the historical archive. Its archived status does not establish when or how the reported situation ended.

Source and dates
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · WZ 360/21 301720Z MAR 21.. Issued 2021-03-30 17:23Z. First collected 2026-08-17 13:38Z; last seen in collection 2026-08-17 15:46Z. Collection dates record ingestion, not a new incident or a fresh field observation.
Location covered
Irish Sea and St. George's Channel. The map shows the reported line or operation extent; it is not a vessel track. Check the original wording for limits and qualifications.

Current notices and reporting history in the Irish Sea and St. George's Channel →

issued
2021-03-30 17:23Z
status
Archived notice
authority
WZ 360/21 301720Z MAR 21.
issued by
WZ
sea
Irish Sea and St. George's Channel
position
53.805, -4.503
vessel
C/S ILE DAIX
source
NGA MSI broadcast-warn JSON (archive, frozen 2024-05) · first seen 2026-08-17 13:38Z

Original warning text

IRISH SEA.
DNC 20.
UNDERWATER OPERATIONS IN PROGRESS UNTIL FURTHER
NOTICE BY C/S ILE DAIX IN VICINITY OF TRACKLINE JOINING
53-48.7N 004-31.0W, 53-47.9N 004-29.4W
ONE MILE BERTH REQUESTED.

Reading this warning

DNC (Digital Nautical Chart)
A reference to one of the regions of NGA's Digital Nautical Chart, used to tell the reader which charts a warning affects.
Underwater operations
Divers or remotely operated vehicles are working below a vessel that cannot easily move out of the way.
Until further notice
The operation or danger has no scheduled end; the warning stays in force until a later message cancels it.
Track line joining
Introduces a route through a series of positions — a cable route, a tow's track or a survey line.
Position (degrees and minutes)
How warnings write positions: degrees, a hyphen, then minutes, with N/S and E/W — 49-40.8N 003-43.8W.
Wide berth requested
Keep well clear — or, when a distance is given ("TWO MILE BERTH REQUESTED"), at least that far away.

All warning terms →

Collected reports in this area · survey operations

446 within 180 nm since 1999 · 1 in the last 12 months · 0 listed in force now

99
00
05
10
15
20
25
26

Counts include repeat notices about the same situation. NGA archive coverage ends 2024-05; live collection began 2026-08-17. The period between them is incomplete. An empty year is not evidence that no hazards occurred.

Month of issue in the collected archive

J
F
M
A
M
J
J
A
S
O
N
D

All available years combined. Uneven collection and repeat bulletins affect these counts; this chart does not measure the seasonality or probability of incidents.

Nearby notices listed in force · within 120 nm

No other collected notice is currently listed in force within this radius. This does not establish safe conditions.

Worldwide in the collected sources

56 survey operations listed in force · see all

Record snapshot 2026-10-02 16:44Z; source collection times vary.

Surveys

Hydrographic and scientific survey vessels, often towing long arrays. All current survey operations →

Not for navigation. This is a re-rendering of an official navigational warning for awareness; mariners must use official NAVAREA broadcasts and their national MSI service.